increasing roi with commercial-scale inverters sponsored by:
TRANSCRIPT
Increasing ROI With Commercial-Scale Inverters
Sponsored By:
This webinar will be available afterwards at www.solarpowerworldonline.com & via email
Q&A at the end of the presentation
Hashtag for this webinar: #SolarWebinar
Before We Start
Moderator
Steven Bushong
Solar Power World
Presenters
Scott KolekAdvanced Energy
Jon FiorelliSolectria
Opportunities for Increasing ROI of
Commercial PV InvertersScott Kolek – Product Manager - TX Inverters
AE Solar Energy
Agenda
Brief introduction to Advanced Energy
‘Typical’ Large-scale Commercial PV
Installation
Technologies and Products for ROI
Optimization
Traditional
New
Emerging
Conclusions and Takeaways
Advanced Energy Overview30-year focus on power conversion solutions
• Founded in 1981 in Ft. Collins, Colorado• 5 major sites: Fort Collins, Colorado; Bend, Oregon; Toronto, Ontario; Metzingen,
Germany; and Shenzhen, China• 1571 employees worldwide (as of May 2013)• Dedicated service organization
2012 revenue $452M• Ended 2012 with $172.2M in cash, having generated $110.8M of cash in 2012
Market capitalization $676.42M (as of May 13, 2013) • Two business units
• AE Thin Films: Power conversion solutions for thin-film plasma manufacturing
• AE Solar Energy: PV inverters and energy management solutions• Solid footing in growing solar inverter market
• Leadership in North America
AE Solar Energy Global Footprint
Transformer and transformerless PV inverters, integrated solutions, complementary BoS products, and O&M aimed at lowest cost of energy through
project life-cycle
Product Power Levels & Market Segments
Integrated SolutionsPower: 500 – 2MW
CentralPower: 35 – 500kW
StringPower: 12 – 24kW
Traditional Large-scale Commercial PV
InstallationTypical Characteristics
• Rooftop mounted, 600 VDC Strings
• ~12 panels/circuit
• DC Combiner Boxes
• Pad/Ground-mounted Central Inverters, ~100KW to 500KW range
• DC:AC Ratio on order 1.1-1.25:1
• DC Sub combiners (fuses or breakers) integral to inverters
• Inverter-level and (sometimes) sub combiner monitoring
3MW Rooftop Solution, Ontario CA250kW & 500KW Central Inverters
2.4MW Rooftop Solution, Portland OR100kW & 260KW Central Inverters
Traditional Methods – ROI ImprovementBoS Cost Reductions
Structural system – optimized for streamlined installation
Reduce install labor - pre-assembly, on-site assembly line, etc.
Reduce O&M Costs – Reliability, increased uptime
Wiring reduction methods (CPT, RPT)
MV Applications: Multiple inverters 1 Step up transformer
Increase Energy Harvest Increase panel performance
Inverters lifetime = module lifetime
Increased inverter reliability & uptime
Increased inverter efficiency
Trackers
MPPT – Wider range, improved algorithms
Use of modeling for design optimization
New Methods – Distributed/String InvertersROI-Enhancing Benefits:
Optimal match of power conversion capacity to array capacity – using smaller 15-24kW inverter blocks
Eliminate DC Combiner Boxes (note: AC combiners still required)
Reduced cost of (commodity) AC aggregation equipment versus low volume/high cost DC equipment
Less mounting space. Compact size allows close-proximity mounting to array. No pad or rigging.
Multiple MPPT Trackers on each roof offset shading & less-than-optimal array orientations
Rapid field replacement serviceability
Build-in monitoring capability for each inverter
100kW Rooftop Solution, Piscataway, NJ20 & 24kW String Inverters
New Methods – High DC:AC Ratio StringingROI-Enhancing Benefits:
Low (and lowering) cost of panels permit higher panel densities at small overall cost impact
Utilize higher DC:AC Ratios to increase time at full power and increase Capacity Factor (Actual Energy / Max. Potential Energy)
Achieve increased energy harvest in high temperature climates and less-than-optimal array mounting configurations
CEC efficiency & MPPT less relevant in high DC:AC ration systems.
DC:AC ratios 1.75-2:1 are available.
Emerging Methods – 1000V DC for
CommercialUL-Listed installations are happening
• Utility, commercial ground mount and rooftop
Many developers & EPC’s going to 1kV DC• Both central and string• Projected to become mainstream solution for large
commercial applications
No NEC barriers, AHJ roadblocks clearing• 1000 VDC on commercial rooftop and ground mount
today with minimal challenges• Ambiguity in code slowly being cleared up,
acceptance accelerating
1000 VDC equipment selection growing• Driven by growth of Utility segment• Including modules, inverters, combiners, BOS
ROI-Enhancing Benefits: 20 modules per 1000 Vdc string vs. 12 per string at 600 Vdc in same location =
• ~40% less strings for same power, ~40% less combiner boxes, ~40% less home runs
Conductor savings• “Amps cost $, volts are free” : This is almost true, 1000 Vdc PV wire costs
more that same gauge 600 Vdc wire, but it carries far more energy • ~40% less conductor costs. • Lower voltage drop losses• Less losses from strings to combiners
1000V DC Commercial PV – The Upsides,
Downsides
Downsides: Requirement to meet >600V (multiple) sections code can complicate AHJ
approval 1000V equipment availability still biased towards large scale utility applications
(but changing…) Additional permitting and inspection “hoops” may offset benefits Short cable length & restrictive wiring applications may limit benefits Additional safety & training considerations for higher/1000V
Farther out – PV/Battery & Intelligent
MicrogridsConcept:• Battery storage + PV
array become ”dispatchable” power supply asset
• Enterprise Controls intelligent dispatch generation sources + load controls to optimally-reduce energy costs
• Reduce size and usage of diesel gens for standby power. Reduce UPS.
• Participate in Energy Markets and sell excess electricity when prices high
Utility Supply
Solar PV
…
PCC
Enterprise Level Control
Facility Loads
Facility Grid
Battery Storage
Standby Generators
Utility Master Control
+++
---
Inverter
Hybrid PV/Battery System
Load Shed/Add
Rev. meter,Grid/Island
Start/StopLoad LevelCharge/
DischargeLoad Level
Load LevelpF Level
How AE is Addressing the ChallengesContinued Product Development
• 1000V Solutions• Distributed/String solutions
Forward-thinking R&D and Technology Partnerships• SEGIS-AC and SEGIS: 4 years and counting
• Partnering with industry leaders to develop collaborative solutions: PGE, PEPCO, SAFT, NPPT, Sandia, NREL, etc
• 3+ year relationship with Schweitzer Engineering Lab (SEL) to advance technologies and products related to utility, facility, and PV system integration
• Closed-loop controls, advanced anti-islanding, reliability and stability, cyber-security
Thinking beyond the Inverter• PowerStation packaging, hybrid power system, energy storage, advanced
inverter master controllers, etc.
Thank you for your attention!
AE Solar Energy Headquarters20720 Brinson BlvdBend, OR 97701www.advanced-energy.com/solarenergy
Scott KolekProduct Manager – TX InvertersAE Solar Energy+1.970.492.2028 [email protected]
Increasing ROI with Commercial Scale Inverters
Jon FiorelliApplications Engineer
Solectria Renewables
Topics Covered
1. Design Considerations…2. Inverter Integrated Options…3. Post-Inverter Installation
Considerations…
…that impact ROI
Design Considerations
Design Considerations
There are dozens of design decisions Cost/Benefit Analysis
Financial Model Keep in mind that there are many
design decisions that are difficult to quantify
There are very few “Rules of Thumb” Project Goals and Challenges Vary Financial Models Vary
String SizingUse Max Allowable String Size to: Reduced BOS Costs (Fewer strings means fewer combiner
boxes and fewer source and output circuits) Reduce System Losses (fewer circuits and higher
voltage/lower total current) Maximize Production for System Life Ensures that max
power voltage of the array will stay within the Max Power Point Tracking range of inverter as modules degrade during the lifetime of the system
Of course, using max. number of modules is not always possible or preferred for other reasons (complex layout, odd string size, carport…)
Next Stage in Design Evolution: 1000V Systems
String Sizing - Design Temperatures
Consider using…
ASHRAE Temperature (Extreme Annual Mean Minimum Design Dry Bulb Temperature) for larger max string size NEC 2011 690.7(A) Informational Note Read: “Array Voltage Considerations”,
B. Brooks, SolarPro Oct/Nov 2010 CHECK WITH INSPECTOR!! SolarABC’s Map Tool
www.solarabcs.org/about/publications/reports/expedited-permit/map/
String Sizing Example
Use Solectria PV System Builder (www.solren.com)• Location: Atlantic City, NJ• Array Size: 600kW DC • Module: Sharp NU-U235F1• Inverter: PVI 500
Record Low/Average High
-23°C/29°CÞ 13 Modules Per StringÞ 196 Strings
ASHRAE
-16°C/33°CÞ 14 Modules Per StringÞ 182 Strings
THAT’S ONE LESS 14-STRING COMBINER!!
Oversizing Historically, designers oversize by 10% to 25%
optimize kWh/kW (Specific Yield) -> High Module Prices
Times have change: Cheaper Module Prices (More production for less
incremental cost, same fixed cost) Time-of-Use Utility Rate structures
Limiting factor is short circuit current Designers can vary tilt angle, power density, and
encroach into shaded regions Definition of “Best” Ratio => Optimizes financial model
(IRR, NPV, LCOE) Perform Oversizing Analysis using simulation program
(PVsyst, PV*SOL, SAM) which feeds financial model
Other Design Decisions
Inverter Location (longest run DC or AC?) Inverter Efficiency Module Specs: Efficiency, IP rating, Loading specs Module Tilt Angle/Orientation/Inter-row separation/Power
Density Small vs. Large Combiner Boxes Copper vs. Aluminum Wiring
Inverter Integrated Options
Inverter Integrated OptionsSave field labor, equipment costs, and engineering/procurement overhead by having inverter options factory integrated.
Examples: Subcombiners (Fuses, Breakers) Revenue Grade Meter Monitoring
Gateway Card Zone Level Monitoring (troubleshooting value) Same company for inverter/monitoring
(troubleshooting value)
Post-Installation Considerations
Post Installation Considerations
Means to Ensure UPTIME and Minimize DOWNTIME Perform Preventative Maintenance Inverter Provider Preventative Maintenance Plans Inverter Provider Uptime Guarantee Monitoring with Fault Notification Alerts Fault Action Plan (Installer, O&M Provider, Inverter
Company) Spare Parts?? (Ground Fault Fuse, Subcombiner Fuses) Service and Maintenance Friendly Design (Site Plan
Placards, Shade structure, Service receptacles)
Jon Fiorelli – Applications Engineer
Don’t forget that Application Engineers can help increase ROI:
**Product Knowledge**
**Project Experience**
Thank You!
Questions?Solar Power WorldSteven [email protected] Phone: 440.234.4531Twitter: @wtwh_renewables
SolectriaJon [email protected] Phone: 949.933.6828
Advanced EnergyScott [email protected] Phone: 1.970.492.2028
Thank You This webinar will be available at
www.solarpowerworldonline.com & email
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